There's really not that much violence, 3 scenes where Ender responds with preemptive strikes to sort out dangerous bullying. All of which were engineered or at least allowed to happen by his teachers. Two of which were fatal, but Ender was shielded from this information (though he knows deep down). The rationale being that if he's "the One", he must defeat every challenge regardless of the damage or consequences. The fact that a large part of his gifted strategic genius is his ability to empathize with his enemy makes his trials semi-tragic.
Anyway, I see no need to utilize shakycam for 3 quick scenes where the drama and tension are in Ender's head...the action once he makes his decision is over in a heartbeat.